Were ancient foxes far more carnivorous than recent ones?-Carnassial morphological evidence

In Vitro Analysis of Enamel Patterns Across Three Species Using Stereomicroscopy

Background Dental enamel, the outermost layer of the tooth, stands as a unique and remarkable tissue that plays a crucial role in safeguarding teeth against various external factors. The examination and analysis of enamel rod end patterns on tooth surfaces, referred to as ameloglyphics, offer a promising avenue for dental identification and forensic investigations in forensic medicine, thereby enhancing the precision and reliability of forensic analyses. This paper aims to evaluate and compare the ameloglyphics of different species under a stereomicroscope. The species examined in this study include the beaver (genus Castor), fox (genus Vulpes), and human (Homo sapiens). Methods Teeth samples from each species (n = 3) were gathered from the tooth repository and examined under a stereomicroscope at various magnifications, both with and without graphite staining. Photographs were captured, and the enamel patterns were meticulously evaluated. Through the utilization of plot profiles, the enamel patterns of the different species were compared, and any discernible differences between them were carefully noted. Results The plot profiles of the three species were analyzed, revealing distinct characteristics. Specifically, it was observed that the plots of the genus Castor teeth and Homo sapiens teeth exhibited dispersed arrangements, whereas the plot profile of the genus Vulpes displayed a closely arranged pattern. Conclusions Within the confines of the current investigation, it can be inferred that every mammal exhibits a distinct and exclusive arrangement of enamel rods. Hence, the task of identifying a deceased individual through dental imprints may pose difficulties if the structural characteristics are not thoroughly comprehended.

Morphometric analysis of the red fox molar teeth in Lithuania

The objective of the study was to investigate the lengths and widths of maxillary (P⁴ , M¹ and M² ) and mandibular (M₁ , M₂ and M₃ ) molar teeth, lengths of dental rows and dental features of sexual dimorphism in the red fox. The correlation analysis between teeth measurements and dental row length was included too. The osteometric analysis was performed by the A. von den Driesch (1976) method. A total of 230 skulls and mandibles were investigated (n = 230): 113 males (n = 113) and 117 females (n = 117). The findings of the research revealed that most dimensions are higher in males compared with females (p < 0.001). Contrarily, Wilks' Lambda analysis showed results in the interval from 0.821 to 1, which leads to the conclusion that a teeth measurement study is unreliable to determine the sex of the red fox. The trustworthy measurements were the length of the whole dental arcade in the maxilla and mandible (UDR and LDR); Wilks' Lambda UDR = 0.860; LDR = 0.821; p < 0.001). Evaluation of the correlation between measurements revealed that results vary from very weak (0.047) to moderate strength (0.543). There were no strongly correlating measurements found. The correlation between the upper and lower molars with the length of the teeth arcade is quite weak, and only solitary measurements (M² , L and B) had a weak correlation.

Fox (Vulpes vulpes) involvement identified in a series of cat carcass mutilations

This study was designed to identify the cause of mutilation and death in 32 cats, part of a larger cohort found dead in Greater London, the United Kingdom, between 2016 and 2018. At the time, discussion in the media led to concerns of a human serial cat killer (dubbed The Croydon Cat Killer) pursuing domestic cats, causing a state of disquietude. Given the link between animal abuse and domestic violence, human intervention had to be ruled out. Using a combination of DNA testing, computed tomography imaging, and postmortem examination, no evidence was found to support any human involvement. Instead, a significant association between cat carcass mutilation and the presence of fox DNA was demonstrated. Gross examination identified shared characteristics including the pattern of mutilation, level of limb or vertebral disarticulation, wet fur, wound edges with shortened fur, and smooth or irregular contours, and marks in the skin, muscle, and bone consistent with damage from carnivore teeth. Together these findings supported the theory that the cause of mutilation was postmortem scavenging by red foxes (Vulpes vulpes). The probable cause of death was established in 26/32 (81%) carcasses: 10 were predated, 8 died from cardiorespiratory failure, 6 from blunt force trauma, one from ethylene glycol toxicity, and another from liver failure. In 6 carcasses a cause of death was not established due to autolysis and/or extensive mutilation. In summary, this study highlights the value of a multidisciplinary approach to fully investigate cases of suspected human-inflicted mutilation of animals.

Fox dietary ecology as a tracer of human impact on Pleistocene ecosystems

Nowadays, opportunistic small predators, such as foxes (Vulpes vulpes and Vulpes lagopus), are well known to be very adaptable to human modified ecosystems. However, the timing of the start of this phenomenon in terms of human impact on ecosystems and of the implications for foxes has hardly been studied. We hypothesize that foxes can be used as an indicator of past human impact on ecosystems, as a reflection of population densities and consequently to track back the influence of humans on the Pleistocene environment. To test this hypothesis, we used stable isotope analysis (δ¹³C, δ¹⁵N) of bone collagen extracted from faunal remains from several archaeological sites located in the Swabian Jura (southwest Germany) and covering a time range over three important cultural periods, namely the Middle Palaeolithic (older than 42,000 years ago) attributed to Neanderthals, and the early Upper Palaeolithic periods Aurignacian and Gravettian (42,000 to 30,000 years ago) attributed to modern humans. We then ran Bayesian statistic systems (SIBER, mixSIAR) to reconstruct the trophic niches and diets of Pleistocene foxes. We observed that during the Middle Palaeolithic period, when Neanderthals sparsely populated the Swabian Jura, the niches occupied by foxes suggest a natural trophic behavior. In contrast, during the early Upper Palaeolithic periods, a new trophic fox niche appeared, characterized by a restricted diet on reindeer. This trophic niche could be due to the consumption of human subsidies related to a higher human population density and the resulting higher impact on the Pleistocene environment by modern humans compared to Neanderthals. Furthermore, our study suggests that, a synanthropic commensal behavior of foxes started already in the Aurignacian, around 42,000 years ago.